Python-13 函数，Python的乐高积木

函数 

函数的创建和调用

>>> def MyFirstFunction():print('hello world')print('this is my first function')>>> MyFirstFunction()hello worldthis is my first function>>> 

如果调用没有定义的函数名

>>> MySecondFunction()Traceback (most recent call last):  File "<pyshell#5>", line 1, in <module>    MySecondFunction()NameError: name 'MySecondFunction' is not defined>>> 

函数中增加参数

>>> def MySecondFunction(name):print('Hi '+name)>>> MySecondFunction()Traceback (most recent call last):  File "<pyshell#9>", line 1, in <module>    MySecondFunction()TypeError: MySecondFunction() missing 1 required positional argument: 'name'>>> MySecondFunction('Ethan')Hi Ethan>>> 

函数增加return

>>> def MyThirdFunction(num1,num2):result = num1 + num2return result>>> MyThirdFunction()Traceback (most recent call last):  File "<pyshell#15>", line 1, in <module>    MyThirdFunction()TypeError: MyThirdFunction() missing 2 required positional arguments: 'num1' and 'num2'>>> MyThirdFunction(3,5)8>>> 

>>> print(MyThirdFunction(3,5))8>>> 

python的参数可以有多个，但不建议过多，不便于维护。

函数，对象，模块